Detection of liver hemangiomas by Tc-99m-labeled red blood cells

The differentiation of hemangiomas and liver cysts (5-15% in adult population) from single metastases, hepatocellular carcinomas, adenomas and focal nodular hyperplasia is important because of the current aggressive surgical approaches to the treatment of single malignant lesions. Very vascular lesions (focal nodular hyperplasia, some adenomas, some hepatocellular carcinomas, and vascular metastases) show radiological contrast in bolus in the first 30 seconds (the arterial dominant phase). During the delayed contrast enhancement phase (from 30 to 180 seconds), some hepatocellular carcinomas, metastases and occasional hemangiomas may be seen. The accumulation of tagged red blood cells in the hemangioma is much slower than of the contrast, and their activity persists for a much longer time (30 minutes - 2 hours). Data from literature show that hemangiomas larger than 2 cm are detected in 95 %% of cases. In our study we have labeled the red blood cells in vivo with Tc-99m-PYP or Tc-99m-DTPA. Planar scintigrams in several projections are made from 3 to 30 minutes, in matrix 256x8. In 11 of 42 cases one or two very vascular lesions, larger than 2 cm, were found. In four cases the increased activity accumulation was marked as suspect, and in others the increased activity accumulation was not detected. (author)